Automatic safety shutqff system for



June 5, 1951 F. M. WOLFE AUTOMATIC SAFETY SHUTOFF SYSTEM FOR GAS BURNERSCOMPRISING TWO LATCHING MEANS 2 Sheets-Sheet 1 Filed March 4, 1947//VVE/v 70R. flora M. WOLF/E June 5, 1951 BURNERS COMPRISING TWOLATCHING MEANS Filed March 4, 1947 9 24 zany/a 25 2 j: Z 6/ a 28 52 illq m 0 a 7 -g0 I 1 6 i n 50 53 8 I 1 49 ,7

a 4/ 49 '1 I ,M 48 :7 i ,0 47 7 H 1/ if r 45 :3: w z 46 2 Sheets-Sheet 2lNVENTO/E FLOYD M WOLFA'.

A 7' TORNE V.

Patented June 5, 1951 UNITED AUTOMATIC SAFETY SHUTOFF SYSTEM FOR GASBURNERS COMPRISING TWO LATCH- ING MEANS Floyd M. Wolfe, Denver, 0010.

Application March 4, 1947, SerialNo. 732,185

11 Claims. I

This invention relates to. a gas burner safety control and has. for itsprincipal object the provision of means. for controlling the gas supplyto a gas burner in consequence of the operation of the pilot lightemployed for ignitin the burner so that gas cannot flow to either theburner or the pilot burner unless the latter is. properly ignited.

Accidents often occur from the use of gas burners due to the fact thatthe pilot burner will become extinguished from down drafts or from othercauses. The thermostat controlling the main valve will then turn the gasinto the main burner, filling the fire-box with raw explosive gas.

An object of this invention is to provide a. device which willautomatically close the gas supply line to the main burner whenever thepilot burner becomes extinguished, and to provide means which. willprevent the main gas supply line from being opened until the pilotburner has.

been. properly ignited.

Devices have been arranged to electrically shutoff the gas supply to amain burner in case the pilot burner is extinguished. These devices,however, do. not operate to shut off the supply of gas to the pilotburner, and as a result the raw pilot burner gas will often fill thefire-box to an explosive extent.

Another object of this invention is to provide means. which, when thepilot burner is accidentally extinguished will not only shut. off themerals refer to like parts in all views of the.

drawing and throughout the description.

In the drawing:

Fig. 1 is a plan view of the improved burner control in the normaloperating position;

Fig. 2 is alongitudinal section thereof taken on the line 2-2, Fig. 1;

Fig. 3 is avertical cross section taken on. the line 33 Fig. 2;

Fig; 4 is a horizontal cross section taken on the line 4--4, Fig. 5;"

Fig. 5 is a vertical section taken on the line 5-5, Fig. 2, with thecontrol shown in the starting or igniting position;

Fig; 6 is an enlarged, vertical, detail section taken on the line 66,Fig. 4;

Fig. 7 is a similarly enlarged, vertical detail section taken on theline 1-1, Fig. 4; and

Fig. 8 is a similarly enlarged, horizontal detail section through thepilot burner, taken on the line 8-8, Fig. 3.

The invention is designed to control the gas supply line to anyconventional gas burner bymeans of a control valve, designated in itsentirety by the numeral to. The control valve contains an intake chamberH and an outlet chamber l2 provided with the usual threaded pipereceiving sockets 13. The fiow of gas from the chamber II to the chamber12 is controlled by means of a disc valve l4 positioned to contact avalve seat l5.

The disc valve [4 is provided with a valve stem l6 which extendsupwardly through a suitable packing gland I! and through a control boxiii; The valve stem I6 is provided, within the. box ill, with an upperflange 19 and a lower flange 2B. A compression spring 2! acts againstthe upper flange H] to urge the. valve disc: [4 towards its seat I 5.

The valve [4 is supported in the open position of Fig; 2 by means of aswinging latch 23 carried bya locking lever 22 mounted on latch pin 25.The latch 23 is constantly urged toward the up 'per flange is by asuitable torsion spring 24. The spring 24 engages the lever 22 at its:one extremity and engages a fulcrum pin 69 at its other extremity sothat the reaction of the spring is carried to the lever 22. The lowerextremity of the locking lever 22 is provided with a pointed. tooth 26-which engages a toothed rack 2'! on the upper surface of a. horizontallypositionedcontrol bar 28.

The control bar 28 is slidably mounted so that it may be moved back andforth. through the medium of a connecting rod 29 which extends to athermostatically expansible bellows 30; The bellows 30 is positioned ina protecting. frame 3| positioned adjacent the fire box or burner of theheat plant. A supporting tube 32 extends from the frame 3|. to thecontrol box |8.about the connecting rod 29.

The bellows 30 terminates in an expansion chamber 33 positioned adjacentthe pilot. flame from a pilot burner tip 34 so that the head thereofwill expand the bellows 39 so as to forcev the control bar 28 to theleft in Fig. 2. This moveallows the valve M to drop under the influenceof the spring 2| so as to shut off the supply of gas to the outletchamber l2 and to the main burner.

The lug shaft 59 also carries a second lug 6| positioned at right anglesto the first lug 58. When the valve i4 opens, the lug shaft will berotated to bring this second lug in the path of a second dog 61, mountedon the cam 53 to lock the valve 43 in the normal position of Fig.

Let us assume that the mechanism is in the position of Fig. 2 and thatgas is flowing from the intake chamber I! to the outlet chamber |2 andfrom thence to the burner and through the passage 42, valve 43, and tube39 to the pilotlight.

' The mechanism remains in this position as long The control rod 28 isprovided on its underside with a second tooth-ed rack which acts againsta pointed extremity 36 on a second locking lever 3! to swing the latterto and from the lower disc 20. The second lever 31 is provided with alatch member 38 which, when the control rod 28 moves to the right,swings above the lower flange 20, as shown in broken line in Fig. 2, toprevent the valve M from being opened. When the control rod 28 moves tothe left under the influence of the expanding bellows 39 the secondlockinglever 31 will be swung to the solid line position of Fig. 2 so asto release the flange 20 and allow the valve I4 to be'opened, as will belater described.

The gas is fed to the pilot burner through a gas, tube 39 extending to apilot burner valve housing 49 formed, or secured, on the side of thecontrol valve l0. Two passages 4| and 42 communicatebetween the pilotburner housing 40 andthe intake chamber I and the outlet chamber I2,respectively. The passages 4| and 42 are controlled by means of atwo-way plug valve 43 maintained in a tapered valve seat by means of avalve spring 44. i

The plug valve 43 is provided with two ports 45 and 46 which open thepassages 4| and 42, respectively, to the hollow interior of the valve43. The ports 45 and 45 are positioned at right angles to each other.The gas from either passage discharges from the hollow interior of thevalve 43 through a discharge port 41 to an annular receiving chamber 48communicating with the gas tube 39.

The pilot burner valve 43 may be rotated from a Valve shaft 49 whichextends through a cam 'box 59 and terminates in a control handle 5|.

The control handle 5| is constantly urged toward the position of Figs. 1and 3 by means of a return spring 52. To open the port 46 to the passage4| it is necessary to manually rotate the handle 5| against the actionof the spring 52 to the position of Fig. 5.

The valve shaft 49 is provided with a cam 53 against the cam surface ofwhich a cam follower 54 bears. The cam follower is pivoted on a cam pin55 and is provided with a bifurcated spring arm 56 which extends beneaththe lower flange 20. When the lever 5| is swung from the position ofFig. 1 to the position of Fig. 5, the cam 53 will force the follower 54downwardly, putting tension in the spring arm 56 to urge the valve stemIE to open the Valve [4. The lever 5| is temporarily held in theposition of Fig. 5 by means of a swinging dog 51, which engages a lug asthe pilot light is lighted.

Now let us'assume that the pilot burner becomes extinguished. Thiscauses the bellows 3D to contract to pull the latch member 22 frombeneath-the upper flange l9 to the spring 2| to V the'burner, for thevalve I4 is locked closed by 58 carried on a rotatable lug shaft 59which exmeans of the locking lever 31. The lever 5| remains in theoperating position of Fig. l.

To start the burner, the lever 5| is turned from the position of Fig. lto the starting or igniting position of Fig. 5. the intake'chamberthrough the passage 4|, and the tube 39 to the pilot burner. isautomatically locked in this position by the dog 5'! and lug 58. Thepilot flame is now ignited.

As soon as the pilot flame has heated the expansion chamber 35sufficiently, the bellows will expand to the left swinging the lockinglever 31 away from the flange 20 and allowing the spring arm 56 to snapthe valve |4 open and allowing theflange I9 to move past the latchmember 22 to lock-the valve open. In moving to the open posie tion'theflange 25 will, through the medium of the arm 69, rotate the shaft 59 toswing the lug 58 from the path of the dog 51. This allows the spring 52to return the pilot burnervalve 43 to the position of Fig. 3 so that gaswill flow through the passage 42 and port 46 from the outlet chamber l2to the pilot burner. When the handle 5| reaches the position of Figs. 1and 3 the second dog '51 will engage the second lug 6| to lock the valve43 open and to prevent the pilot burner gas from being shut off. 7

Thus it can be seen that gas cannot flow to the burner unless the pilotburner has been lighted, and that no gas can flow to the pilot burneruntil it is reignited.

There might be emergencies arise in which the pilot burner would becomeextinguished before it had heated the expansion bellows to a point tooperate the valve, and since the pilot burner valve is locked in theopen position of Fig. 3 by the latch member 6|, it would be impossiblefor the operator to shut off the burner.

For such cases, a sliding sleeve62 may be provided on the shaft 59 forcarrying the lugs 58 and 6|. This sleeve is keyed to the shaft 59 bymeans of a key '63 riding in an elongated slot 64 in the sleeve 62.Outward movement of the sleeve 62 is prevented by means of a tubular cap65 which extends to the exterior of the ,cam box 59. The cap is normallyprevented from moving outward by means of a boss 66 which bears againstthe side of the box 59. When the cap 65 is turned to one position theboss 66 may exit through a slot 61 to allow the cap to move outward sothat the lug 58 may move out of the way of the dog 51 so that the spring52 may This allows gas to flow from The handle gas to the extinguishedpilot return the pilot burner valve to the inoperative position.

While a specific form of the improvement has been described andillustrated herein, it is desired to be understood that the same may bevaried, within the scope of the appended claims, without departing fromthe spirit of the invention.

Having thus described the invention, what is claimed and desired securedby Letters Patent is:

1, In combination, a pilot burner; a thermoexpansible unit placed toreceive heat from said pilot burner; a control bar longitudinallymovable by said thermo-expansible unit; a main gas valve; a pilot gasvalve; a locking latch for holding said main valve open; a secondlocking latch for holding said main valve closed; and means on saidcontrol bar for actuating the second latch to the holding position andreleasing the first latch when said thermoeexpansible unit contracts andfor actuating the first latch to the holding position and releasing thesecond locking latch when said thermo-expansible unit expands.

2. A control for gas burners comprising: a pilot burner; athermo-expansible unit placed to receive heat from said pilot burner; acontrol bar longitudinally movable by said thermoexpansible unit; a maingas valve; spring means urging said main valve closed; a pilot burnervalve; a locking latch for holding said main valve open; engaging meansoperable from said control bar for actuating said latch to the holdingposition; releasing means operable by said control bar for releasingsaid latch from said main valve so that said spring means will close thelatter when the pilot burner is extinguished; and means operable fromsaid pilot burner valve for exerting an opening action on said main gasvalve when said pilot burner is operated to turn gas to said pilotburner.

3. In a device of the class described, a main valve body having anintake chamber and a discharge chamber; a valve disc controlling theflow from said intake chamber to said discharge chamber; resilient meansurging said valve disc to the closed position; a valve stem extendingfrom said disc; a control bar extending laterally across said valvestem; a pilot burner; a thermoexpansible member positioned adjacent saidpilot burner; a connecting rod connected between said therrno-expansiblemember and said control bar for moving the latter transversally of saidvalve stem in consequence of the movements of the former; a projectionon said valve stem; a swinging latch adapted to engage said projectionto hold said valve disc open; and means on said control bar positionedto engage said latch to release the latter when said pilot burner isextinguished to allow said resilient means to close said valve.

4:. In a device of the class described, a main valve body having anintake chamber and a discharge chamber; a valve disc controlling theflow from said intake chamber to said discharge chamber; resilient meansurging said valve disc to the closed position; a valve stem extendingfrom said valve disc; a control bar extending transversally across saidvalve stem intermediate the extremities thereof; a pilot burner; athermoexpansible member positioned adjacent said pilot burner; aconnecting rod connected between said thermo-expansible member and saidcontrol bar for moving the latter transversally of said valve stem inconsequence of the movements of the former; a projection on said valvestem at one side of said control bar; a swinging latch adapted to engagesaid projection to hold said valve disc open; means on said control barfor engaging said latch to release the latter from said projection whensaid pilot burner is extinguished; a second projection on said valvestem on the other side of said control bar; a second swinging latch forengaging said second projection to hold said valve disc closed; andmeans operable from said control bar for releasing second said latchfrom said second projection when said pilot burner is ignited.

5. In a device of the class described, a main valve body having anintake chamber and a discharge chamber; a valve disc controlling theflow between said chambers; a pilot burner; means for opening andclosing said valve disc in response to the heat from said pilot burner;a pilot valve housing positioned adjacent said main valve'body; a hollowported pilot burner valve in said latter housing controlling the flow tosaid pilot burner; a first passage in said body and housing extendingfrom said intake chamber to said pilot burner valve; a second passage insaid body and housing extending from said discharge chamber to saidpilot burner valve; a third passage in said pilot valve housing; meansfor rotating said pilot burner valve when said main valve is closed soas to place the first passage in communication with the third passage soas to connect the pilot burner with the intake chamher; and spring meansfor returning said pilot burner valve toits former position to place thesecond passage in communication with the third, passage so as to connectthe pilot burner with said discharge chamber when the valve disc isopen.

6. A control for gas burners comprising: a D1101; burner; athermo-expansible unit placed to receive heat from aid pilot burner; acontrol bar longitudinally movable by said thermo-expansible unit; amain burner valve having an intake and a discharge side; spring meansurging said main valve closed; a locking latch for holding said mainvalve open; engaging means operable by said control bar for actuatingsaid latch to the holding position when said pilot burner is ignited;releasing means operable by said control bar for releasing said latch toallow said main valve to close when the pilot burner is extinguished; apilot burner valve, there being a first gas passage communicatingbetween the intake side of said main valve and said pilot burner valveand a second gas passage communicating between the discharge side ofsaid main valve and said pilot burner valve and a third gas passagecommunicating between said pilot burner and said pilot burner valve; anda port in said pilot burner valve positioned to register with each ofsaid passages, said ports being interconnected in said pilot burnervalve so that rotation of the pilot burner valve will place either thefirst or second passage in communication with said third passage andsaid pilot burner.

'7. A control for gas burners comprising: a pilot burner; athermo-expansible unit placed to receive heat from said pilot burner; acontrol bar longitudinally movable by said thermo-expansible unit; amain burner valve having an intake and a discharge side; spring meansurging said main valve closed; a locking latch for holding said mainvalve open; engaging means operable by said control bar for actuatingsaid latch to the holding position when said pilot burner is ignited;releasing means operable by said control 7'. bar forireleasing saidlatch to allow said main valve to close when the pilot burner isextinguished; a pilot burner valve, there being a first gas passagecommunicating between the intake side of said main valve and said pilotburner valveand a second gas passage communicating between the dischargeside of said main valve and aid pilot burner valve and a third gaspassage communicating between said pilot burner and said pilot burnervalve; a port in said pilot burner valve positioned to register witheach of said passages, said ports being interconnectedin said pilotburner valve so that rotation of the pilot burner valve will placeeither the first or second passage in communication with said thirdpassage and said pilot burner; a manual handle for rotating said pilotvalve to place said first passage in communication with said pilotburner; and automatic means operable by said main gas valve and actingto return said pilot valve into communication with said second passagewhen said main valve is opened.

8. A control for gas burners comprising: a pilot burner; athermo-expansible unit placed to receive heat from said pilot burner; acontrol bar longitudinally movable by said thermo-expansible unit; amain burner valve having an intake and a discharge side; spring meansurging said main valve closed; a locking latch for holding said mainvalve open; engaging means operable by said control bar for actuatingsaid latch to the holding position when said pilot burner is ignited;releasing means operable by said control bar for releasing said latch toallow said main valve to close when the pilot burner is extinguished; apilot burner valve, there being a, first gas passage communicatingbetween the intake side of said main valve and said pilot burner valveand a second gas passage communicating between the discharge side ofsaid main valve and said pilot burner valve and a third gas passagecommunicating between said pilot burner and said pilot burner valve; aport in said pilot burner valve positioned to register with each of saidpassages, said ports being interconnected in said pilot burner valve sothat rotation of the pilot burner Valve will place either the first orsecond passage in communication with said third passage and said pilotburner; a manual handle for rotating said pilot valve to place saidfirst passage in communication with said pilot burner; means for lockingsaid pilot valve in communication with said first passage; a springurging said pilot valve into communication with said second passage; andreleasing means operable from the opening action of said main valve forreleasing said locking means so that said latter spring may return saidpilot valve into communication with said second passage when said mainvalve is opened.

9. A control for gas burners comprising: a pilot burner; athermo-expansible unit placed to receive heat from said pilot burner; acontrol bar longitudinally movable by said thermo-expansible unit; amain burner valve having an intake and a discharge side; spring meansurging said main valve closed; a locking latch for holding said mainvalve open; engaging means operable by said control bar for actuatingsaid latch to the holding position when said pilot burner is ignited;releasing means operable by said control bar for releasing said latch toallow said main valve to close when the pilot burner is extinguished; apilot burner valve, there being a first gas passage communicatingbetween the in- 8; take side of said main valve. and said pilot burnervalve and a second gas passage communicating between the discharge sideof said main valve and said pilot burner valve and a third gas passagecommunicating between said pilot burner andsaid pilot burner valve; aport in said pilot burnervalve positioned to register with each of saidpassages, said ports being interconnected in said pilot burner valve sothat rotation of the pilot burner valve will place either the first orsecond passage in communication with said third passage and said pilotburner; a manual handle for rotating said pilot valve to place saidfirst passage in communication with said pilot burner; automatic meansoperable by said main gas valve andiacting to return said pilot valveinto communication with said second passage when said main valve isopened; locking means automatically engaging said pilot valve to lockthe latter in communication with said second passage when said mainvalve is opened; and a releasing member extendin from said main valve tosaid pilot valve and arranged to release said locking means when saidmain valve closes.

10. A control for gas burners comprising: a pilot burner; athermo-expansible unit placed to receive heat from said pilot burner; acontrol bar longitudinally movable by said thermo-expansible unit; amain burner valve having an intake and a discharge side; spring meansurging said main valve closed; a locking latch for holding said mainvalve open; engaging means operable by said control bar for actuatingsaid latch to the holding position when said pilot burner is ignited;releasing means operable by said control bar for releasing said latch toallow said main valve to close when the pilot burner is extinguished; apilot burner valve, there being a first gas passage communicatingbetween the intake side of said main valve and said pilot burner valveand a second gas passage communicating between the discharge side ofsaid main valve and said pilot burner valve and a third gas passagecommunicating between said pilot burner and said pilot burner valve; aport in said pilot burner valve positioned to register with each of saidpassages, said ports being interconnected in said pilot burner valve sothat rotation of the pilot burner valve will place either the first orsecond passage in communication with said third passage and said pilotburner; a manual handle for rotating said pilot valve to place saidfirst passage in communication with said pilot burner; automatic meansoperable by said main gas valve and acting to return said pilot valveinto communication with said second passage when said.

main valve is opened; a cam mounted on said pilot valve; a spring armpivoted intermediate its extremities and contacting said cam at its oneextremity and said main valve at its other extremity, said cam' beingcontoured to cause said spring arm to exert an opening action on saidmain valve when said pilot valve is rotated manually by said manualhandle. a

11. A control for gas burners comprising: a pilot burner; athermo-expansible unit placed to receive heat from said pilot burner; acontrol bar longitudinally movable by said thermo-expansible unit; amain burner valve having an intake and a discharge side; spring meansurging 7 said main valve closed; a locking latch for holdbar forreleasing said latch to allow said main valve to close when the pilotburner is extinguished; a pilot burner valve, there being a first gaspassage communicating between the intake side of said main valve andsaid pilot burner valve and a second gas passage communicating betweenthe discharge side of said main valve and said pilot burner valve and athird gas passage communicating between said pilot burner and said pilotburner valve; a port in said pilot burner valve positioned to registerwith each of said passages, said ports being interconnected in saidpilot burner valve so that rotation of the pilot burner valve will placeeither the first or second passage in communication with said thirdpassage and said pilot burner; a manual handle for rotating said pilotvalve to place said first passage in communication with said pilotburner; automatic means operable by said main gas valve and acting toreturn said pilot valve into communication with said second passage whensaid main valve is opened; and a manually actuated release device forreleasing said latter locking means when desired.

FLOYD M. WOLFE.

REFERENCES CITED The following references are of record in the file ofthis patent:

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